MVC上傳圖檔

V：.jsp

C: .servlet

M:.java

功能一：瀏覽圖檔

.jsp 放置圖片路徑

<div>
    <img src="<%=request.getContextPath()%>
    /DBGifReader4?
    emp_photo_no=${empPhSvc.getAllByEMPNO(empVO.getEmpNo()).get(0).getEmpPhtoNo()}"
</div>

.java從資料庫找圖片

@WebServlet("/DBGifReader4")
public class DBGifReader4 extends HttpServlet {

    Connection conn;

    public void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {

        res.setContentType("image/gif");
        ServletOutputStream out = res.getOutputStream();
        req.setCharacterEncoding("UTF-8");

        try {
            String emp_photo_no = req.getParameter("emp_photo_no");
            emp_photo_no = new String(emp_photo_no.getBytes("ISO-8859-1"),"UTF-8");

            Statement stmt = conn.createStatement();

            ResultSet rs = stmt.executeQuery(
                    "SELECT EMP_PHOTO FROM emp_photos WHERE EMP_PHOTO_NO ='"+emp_photo_no+"'");


            if (rs.next()) {
                BufferedInputStream in = new BufferedInputStream(rs.getBinaryStream("EMP_PHOTO"));
                byte[] buf = new byte[4 * 1024]; // 4K buffer
                int len;
                while ((len = in.read(buf)) != -1) {
                    out.write(buf, 0, len);
                }
                in.close();
            } else {
                //res.sendError(HttpServletResponse.SC_NOT_FOUND);
                InputStream in = getServletContext().getResourceAsStream("/noData/noPic.jpg");
                byte[] b = new byte[in.available()];
                in.read(b);
                out.write(b);
                in.close();
            }
            rs.close();
            stmt.close();
        } catch (Exception e) {
            System.out.println(e);
            InputStream in = getServletContext().getResourceAsStream("/noData/noPic.jpg");            
            byte[] b = new byte[in.available()];
            in.read(b);
            out.write(b);
            in.close();
        }
    }



}

功能二：上傳圖檔

.jsp使用form:傳送網頁參數empNo給.servlet

<form>
    action="<%=request.getContextPath()%>/employee/employee.do?action=modifySelf"
    method="post" id="contact_form" enctype="multipart/form-data">
    <input type="hidden" name="empNo" value="${empVO.empNo}">
</form>

.servlet取得String empNo, byte[] empPhoto

if(part.getSize()!=0){
InputStream in = part.getInputStream();
byte[] img = new byte[in.available()];
in.read(img);
EmpPhotosVO empPhotosVO = new EmpPhotosVO();
empPhotosVO.setEmpNo(empNo);//員工編號
empPhotosVO.setEmpPhoto(img);//圖

.servlet將資料傳給.java(service)

empPhotoSvc.updateEmpPhoto(empPhotosVO);

.java(service)將資料傳給.java(dao)

    empPhotosVO.getEmpNo();
    empPhotosVO.getEmpPhoto();
    dao.update(empPhotosVO);

    return empPhotosVO;
}

.java(dao)將資料傳給資料庫

pstmt = con.prepareStatement("update emp_photos set  EMP_PHOTO = ? where EMP_NO = ?");
pstmt.setBytes(1, EmpPhotos.getEmpPhoto());
pstmt.setString(2, EmpPhotos.getEmpNo());
pstmt.executeUpdate();

資料庫更新資料

功能三：預覽上傳圖檔

.jsp